MTFCA Forum

What is the best way to tighten a loose crankshaft front pulley?

New ones are not being made and I have 6 that do not look worn, but all of them are loose.

It appears the crankshaft may have been smoothed with a slight reduction in size.

A new aluminum pulley fits tight, but the pin is right up against the pulley rear and the crank cannot be used.

Put a shim between the crank and the pulley. Cut a strip from a coke can and wrap the crank to get a tight fit.

Wasn’t there a crankshaft shim that was available to use for that from the parts suppliers?

A shim made from a can or something similiar would work too. If you have an old copper head gasket you could use strips from that.

Braze up the ID and rebore to whatever size you need, or locate a socket with an ID slightly smaller than the outside of the pulley boss OD. Heat the pully center red, and force the socket over the boss which will shrink the bore . Then rebore.

I use a large socket ground with a slight taper to resize the stub, then aggressively press back into position.

I have used the can shim method which worked. The best one is the one we used to get from Lang's or Chaffin's which actually had a raised edge on it and the belt is not so apt to slip off. The pin is also often loose. To fix the pin put it across an open vise and hit in the middle with a large chisel. A dull chisel works best so it won't cut the pulley, but will bend it so it will stay put in the pulley. A loose pin can actually sound like a knock at idle because it can move end to end making a clicking noise.
Norm

I use an old drill bushing, press it on it down sizes it then pop it back off.

Cans, clue and poo are all temporary fix's, get the aluminum one that you have turned out so the crank yoke fits, I do that on everyone I've had to fit.

Kerry:

"Cans, clue and poo are all temporary fix's, get the aluminum one that you have turned out so the crank yoke fits, I do that on everyone I've had to fit."

Another permanent fix would be the one a previous owner of my '26 Touring did in the '60s.

Zero rattle...

I heated the center part of mine red hot with an acetylene torch then cooled it with water to shrink the metal. I did this a few times until I shrank it enough I had to tap it on with a hammer.

Hi James,
If a crank has had a pulley rattling on it for some time it will be under sized. The clamp type aluminum pully is usually a good option for this.
I'm not sure I understand the last line in your post? Do you meen the hand crank can not be used? Shims have never worked long term for me.
Cories idea may a good option I have not tried that. I have made a sleave that's I.D. is smaller than the O.D. of the part of the pulley that goe's
on the crank. Pressed it on ( took quite a bit of force ) Then had to press it back off. The I.D. of the pulley then had to be bored on the lathe
to a press fit on the crank. One thing to note if you are driving the pulley on to the crank all of the force you use to drive it on will be exerted
on to the third main bearing unless the end of the crank can be backed up in some way. I used a 16# sledge pushed on the crank flange & then
checked to make sure nothing was bent after.
Craig.

I worked for about 25 years repairing Model Ts with a friend that had a 44 X 66 garage for his day jobs.

He had turned the business over to his sons, but they had 18 different welders, and he could weld anything.

He made several of those pulleys fit better by heating them cherry red with a torch he called a Rose Bud.

Usually, one or two drops in cold water, when hot, would make the pulley fit great!

Unfortunately, I lost a good friend to health problems!

Corey is "Right On" with his suggestion!

Chris, two or three short welds would have probably worked well and be easier to remove later!

J1MGOLDEN wrote: ↑

Sun Jan 14, 2024 12:30 pm

Chris, two or three short welds would have probably worked well and be easier to remove later!

Jim, I agree. My touring was owned by a Ford dealer back then and I can imagine a couple mechanics in the shop contemplating fixing that loose pulley once and for all, the one guy saying to his buddy "hey why don't we just weld the damn thing on ... it's not like we'll be around when the next poor sap has to remove it!". True that, they weren't.

Removing the modern aluminum pully was not very easy either!

J1MGOLDEN wrote: ↑

Mon Jan 15, 2024 10:30 am

Removing the modern aluminum pully was not very easy either!

It helps a bit if you tap a screwdriver into the split to open up the hole a little bit.

There was an Allen screw or bolt that had been pounded to pieces for some reason.

Evidently, the previous owner did not like it either.

The larger pulleys on the later Canadian cars are cast iron. If they get loose, some of the suggested remedies may not work.

However, on the pressed steel pulleys you fellows have, and the earlier small pressed steel pulleys we have, I rebuild the centre. I have a piece of medium wall steel tubing which is slightly over size on the OD when measured against the pulley centre. I bore the centre out of the worn pulley to accept the tubing. In variably, this leaves a collar around the hole due to the radius of the bend in the hub of the pulley, and this helps keep the new sleeve straight. A short length of the tubing is MIG welded into the pulley from the back, and the excess weld machined off. The heavier centre is then bored to suit whatever size the crankshaft may have been worn.

Allan from down under.

I just put a split one (aluminum - new) on an engine here - had to spread it with a screwdriver to get it to go on, roll pin was hard to install and there is a set screw "clamp" in them. It's on now and definitely won't rattle like the old one.

Is the pin far enough forward to let the crank engage the pin?

Does your pulley look like this? This pin is positioned correctly to engage the ratchet properly.

Yes, the roll pins can be difficult to install, but reshaping them to reduce the diameter when the crankshaft hole is not worn helps quite a lot. They can be squashed in a vise along the length to do this as needed.

Loosening the clamp screw or removing it completely for installation may also make slipping it on the crankshaft easier. Additionally, a beat up pin hole often times creates a substantial burr on the edges of the hole that should be filed down smooth.

Dan, I just received a couple of the pulleys in question:

The ratchet teeth if you will, cannot not wrap around the pin, the ratchet hits the back of the pulley wall first, so not enough clearance for the teeth to catch to pin. I tried new crank ratchets, old worn, none will allow the teeth wrap around the pin to prevent slipping when hand cranking.

This is true. I have machined out some of the internal radius & back. Carefully, since the wall gets thin. They can be made to work.

Let me add another method I did today.
I pressed my tapered socket tool first. Tightened the hub a bit, but not enough. The early small pully hub is a bit smaller wall thickness in the hub.
I used locktite 660. Designed to build up the worn shafts for bearing fits. Put it on both surfaces & rotate. You will feel the slop go away & tighten.
Set the ratchet pin. After an hour the pully is tight, not movable.
I have used the 660 before for front wheel bearing races with much long term success.